Over the last few decades, medical experts have changed their thinking on the health effects of some common foods and beverages. Higher-fat foods and some alcoholic beverages like red wine and beer, once viewed as top threats to a healthy lifestyle, are now seen by many as less harmful and even as having some health benefits. But there is perhaps no topic that the medical community has reversed its
thinking on more often than coffee. Since long before the advent of modern medicine, public opinion regarding the health effects of coffee has been diverse and ever-changing. Opinion on coffee's health effects can be traced back several centuries. In the 1600s, doctors in England touted coffee as a cure for alcoholism, but some women complained that coffee was making their husbands impotent. They may have been correct, as caffeine is a
diuretic and can irritate the prostate (dehydration and prostatitis can both lead to erectile dysfunction). In the late 1700s, coffeehouses began opening all over colonial America, where coffee was seen as a healthy stimulant that helped the colonists work longer hours. But by the early 1900s, public concern grew as coffee consumption was blamed for a variety of common ailments, such as nervousness, indigestion, and insomnia. In the 1970s, medical journals published studies that linked coffee consumption with high blood pressure and an increased risk of heart attacks. In 2001, a meta-study indicated that coffee was responsible for a 20% increase in risk for urinary tract cancer. But starting in 2007, to the surprise of many, meta-studies began to show positive health effects of coffee consumption. A 2007 study showed that coffee was viewed by many as "practically a health food." However, CNN also warned that given the long history of flip-flops on the health effects of coffee, medical and public opinion on coffee could easily turn negative again.